From patchwork Wed Mar 23 09:26:36 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lin Ming X-Patchwork-Id: 654741 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p2N9ROvF013802 for ; Wed, 23 Mar 2011 09:29:59 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756028Ab1CWJSx (ORCPT ); Wed, 23 Mar 2011 05:18:53 -0400 Received: from mga14.intel.com ([143.182.124.37]:5458 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755943Ab1CWJSw (ORCPT ); Wed, 23 Mar 2011 05:18:52 -0400 Received: from azsmga001.ch.intel.com ([10.2.17.19]) by azsmga102.ch.intel.com with ESMTP; 23 Mar 2011 02:18:52 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.63,230,1299484800"; d="scan'208";a="407040143" Received: from ant.sh.intel.com ([10.239.97.65]) by azsmga001.ch.intel.com with ESMTP; 23 Mar 2011 02:18:51 -0700 From: Lin Ming To: Len Brown , "Rafael J. Wysocki" , Bob Moore Cc: linux-acpi@vger.kernel.org Subject: [PATCH 3/3] ACPICA: Fix code divergence of global lock handling Date: Wed, 23 Mar 2011 17:26:36 +0800 Message-Id: <1300872396-16522-4-git-send-email-ming.m.lin@intel.com> X-Mailer: git-send-email 1.7.3 In-Reply-To: <1300872396-16522-1-git-send-email-ming.m.lin@intel.com> References: <1300872396-16522-1-git-send-email-ming.m.lin@intel.com> Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Wed, 23 Mar 2011 09:29:59 +0000 (UTC) diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h index 6d512fc..73863d8 100644 --- a/drivers/acpi/acpica/acglobal.h +++ b/drivers/acpi/acpica/acglobal.h @@ -214,13 +214,16 @@ ACPI_EXTERN struct acpi_mutex_info acpi_gbl_mutex_info[ACPI_NUM_MUTEX]; /* * Global lock mutex is an actual AML mutex object - * Global lock semaphore works in conjunction with the HW global lock + * Global lock semaphore works in conjunction with the actual global lock + * Global lock spinlock is used for "pending" handshake */ ACPI_EXTERN union acpi_operand_object *acpi_gbl_global_lock_mutex; ACPI_EXTERN acpi_semaphore acpi_gbl_global_lock_semaphore; +ACPI_EXTERN acpi_spinlock acpi_gbl_global_lock_pending_lock; ACPI_EXTERN u16 acpi_gbl_global_lock_handle; ACPI_EXTERN u8 acpi_gbl_global_lock_acquired; ACPI_EXTERN u8 acpi_gbl_global_lock_present; +ACPI_EXTERN u8 acpi_gbl_global_lock_pending; /* * Spinlocks are used for interfaces that can be possibly called at @@ -228,7 +231,6 @@ ACPI_EXTERN u8 acpi_gbl_global_lock_present; */ ACPI_EXTERN acpi_spinlock acpi_gbl_gpe_lock; /* For GPE data structs and registers */ ACPI_EXTERN acpi_spinlock acpi_gbl_hardware_lock; /* For ACPI H/W except GPE registers */ -ACPI_EXTERN acpi_spinlock acpi_ev_global_lock_pending_lock; /* For global lock */ /***************************************************************************** * diff --git a/drivers/acpi/acpica/evmisc.c b/drivers/acpi/acpica/evmisc.c index 7dc8094..69a3b4a 100644 --- a/drivers/acpi/acpica/evmisc.c +++ b/drivers/acpi/acpica/evmisc.c @@ -284,39 +284,41 @@ static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context) * RETURN: ACPI_INTERRUPT_HANDLED * * DESCRIPTION: Invoked directly from the SCI handler when a global lock - * release interrupt occurs. If there's a thread waiting for - * the global lock, signal it. - * - * NOTE: Assumes that the semaphore can be signaled from interrupt level. If - * this is not possible for some reason, a separate thread will have to be - * scheduled to do this. + * release interrupt occurs. If there is actually a pending + * request for the lock, signal the waiting thread. * ******************************************************************************/ -static u8 acpi_ev_global_lock_pending; static u32 acpi_ev_global_lock_handler(void *context) { acpi_status status; acpi_cpu_flags flags; - flags = acpi_os_acquire_lock(acpi_ev_global_lock_pending_lock); + flags = acpi_os_acquire_lock(acpi_gbl_global_lock_pending_lock); - if (!acpi_ev_global_lock_pending) { - goto out; + /* + * If a request for the global lock is not actually pending, + * we are done. This handles "spurious" global lock interrupts + * which are possible (and have been seen) with bad BIOSs. + */ + if (!acpi_gbl_global_lock_pending) { + goto cleanup_and_exit; } - /* Send a unit to the semaphore */ - + /* + * Send a unit to the global lock semaphore. The actual acquisition + * of the global lock will be performed by the waiting thread. + */ status = acpi_os_signal_semaphore(acpi_gbl_global_lock_semaphore, 1); if (ACPI_FAILURE(status)) { ACPI_ERROR((AE_INFO, "Could not signal Global Lock semaphore")); } - acpi_ev_global_lock_pending = FALSE; + acpi_gbl_global_lock_pending = FALSE; - out: - acpi_os_release_lock(acpi_ev_global_lock_pending_lock, flags); +cleanup_and_exit: + acpi_os_release_lock(acpi_gbl_global_lock_pending_lock, flags); return (ACPI_INTERRUPT_HANDLED); } @@ -350,14 +352,20 @@ acpi_status acpi_ev_init_global_lock_handler(void) * Map to AE_OK, but mark global lock as not present. Any attempt to * actually use the global lock will be flagged with an error. */ + acpi_gbl_global_lock_present = FALSE; if (status == AE_NO_HARDWARE_RESPONSE) { ACPI_ERROR((AE_INFO, "No response from Global Lock hardware, disabling lock")); - acpi_gbl_global_lock_present = FALSE; return_ACPI_STATUS(AE_OK); } + status = acpi_os_create_lock(&acpi_gbl_global_lock_pending_lock); + if (ACPI_FAILURE(status)) { + return_ACPI_STATUS(status); + } + + acpi_gbl_global_lock_pending = FALSE; acpi_gbl_global_lock_present = TRUE; return_ACPI_STATUS(status); } @@ -414,7 +422,7 @@ static int acpi_ev_global_lock_acquired; acpi_status acpi_ev_acquire_global_lock(u16 timeout) { acpi_cpu_flags flags; - acpi_status status = AE_OK; + acpi_status status; u8 acquired = FALSE; ACPI_FUNCTION_TRACE(ev_acquire_global_lock); @@ -458,15 +466,15 @@ acpi_status acpi_ev_acquire_global_lock(u16 timeout) } /* - * Make sure that a global lock actually exists. If not, just treat the - * lock as a standard mutex. + * Make sure that a global lock actually exists. If not, just + * treat the lock as a standard mutex. */ if (!acpi_gbl_global_lock_present) { acpi_gbl_global_lock_acquired = TRUE; return_ACPI_STATUS(AE_OK); } - flags = acpi_os_acquire_lock(acpi_ev_global_lock_pending_lock); + flags = acpi_os_acquire_lock(acpi_gbl_global_lock_pending_lock); do { @@ -475,20 +483,19 @@ acpi_status acpi_ev_acquire_global_lock(u16 timeout) ACPI_ACQUIRE_GLOBAL_LOCK(acpi_gbl_FACS, acquired); if (acquired) { acpi_gbl_global_lock_acquired = TRUE; - ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Acquired hardware Global Lock\n")); break; } - acpi_ev_global_lock_pending = TRUE; - - acpi_os_release_lock(acpi_ev_global_lock_pending_lock, flags); - /* - * Did not get the lock. The pending bit was set above, and we - * must wait until we get the global lock released interrupt. + * Did not get the lock. The pending bit was set above, and + * we must now wait until we receive the global lock + * released interrupt. */ + acpi_gbl_global_lock_pending = TRUE; + acpi_os_release_lock(acpi_gbl_global_lock_pending_lock, flags); + ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Waiting for hardware Global Lock\n")); @@ -496,17 +503,16 @@ acpi_status acpi_ev_acquire_global_lock(u16 timeout) * Wait for handshake with the global lock interrupt handler. * This interface releases the interpreter if we must wait. */ - status = acpi_ex_system_wait_semaphore( - acpi_gbl_global_lock_semaphore, - ACPI_WAIT_FOREVER); + status = + acpi_ex_system_wait_semaphore + (acpi_gbl_global_lock_semaphore, ACPI_WAIT_FOREVER); - flags = acpi_os_acquire_lock(acpi_ev_global_lock_pending_lock); + flags = acpi_os_acquire_lock(acpi_gbl_global_lock_pending_lock); } while (ACPI_SUCCESS(status)); - acpi_ev_global_lock_pending = FALSE; - - acpi_os_release_lock(acpi_ev_global_lock_pending_lock, flags); + acpi_gbl_global_lock_pending = FALSE; + acpi_os_release_lock(acpi_gbl_global_lock_pending_lock, flags); return_ACPI_STATUS(status); } diff --git a/drivers/acpi/acpica/utmutex.c b/drivers/acpi/acpica/utmutex.c index 519d4ee..7d797e2 100644 --- a/drivers/acpi/acpica/utmutex.c +++ b/drivers/acpi/acpica/utmutex.c @@ -93,11 +93,6 @@ acpi_status acpi_ut_mutex_initialize(void) return_ACPI_STATUS (status); } - status = acpi_os_create_lock (&acpi_ev_global_lock_pending_lock); - if (ACPI_FAILURE (status)) { - return_ACPI_STATUS (status); - } - /* Mutex for _OSI support */ status = acpi_os_create_mutex(&acpi_gbl_osi_mutex); if (ACPI_FAILURE(status)) {